Topic 5: Health, disease & development of medicine - PAPER ONE Flashcards

Question

Explain how people can become immune to diseases (long answer)

Answer 1

1) When pathogen enters body for first time, response is slow as there aren't many B-lymphocytes that can make the specific antibody needed to lock on to the antigen 2) Eventually the body will produce enough of the right antibody to overcome the infection, but the person will show symptoms of the disease in the meantime 3) Memory lymphocytes are also produced as well as antibodies in response to a foreign antigen. They remain in the body for a long time and 'remember' the specific antigen 4) So, if the same pathogen enters the body again, more cells will recognise it and produce antibodies against it. This means that this 'secondary immune response' is faster and stronger. It often gets rid of the pathogen before you begin to show symptoms

Answer 2

1) Body injected with dead/inactive pathogens. These carry antigens so, despite them being harmless, your body makes antibodies to help destroy them 2) Antigens trigger memory lymphocytes to be made as well 3) So, if live pathogens of the same type get into the body, there will already be memory lymphocytes to cause a fast secondary immune response and you're less likely to get the disease

Answer 3

Pros: Herd Immunity: If a large percentage of the population are immunised, the people who aren't are unlikely to catch the disease as there are fewer people to pass it on. This helps prevent epidemics. Cons: Doesn't always work (sometimes doesn't give you immunity) You can have a bad reaction e.g. swelling or even a fever and seizures (bad reactions are very rare)

Answer 4

Only bacterial infections - they inhibit cell processes in the bacterium but not the host organism - KILL BACTERIA

Answer 5

Contamination by unwanted microorganisms will affect your results an potentially result in the growth of pathogens. Aseptic techniques are used to avoid this.

Answer 6

- Petri dishes and growth medium must be sterilised before in an autoclave which uses steam at high pressure and temperature. This kills microorganisms. - Inoculating loop sterilised by passing it through a hot flame before being used to transfer bacteria. This kills unwanted microorganisms - Lid on petri dish should be kept closed apart from briefly when transferring the bacteria to prevent other microbes getting in - Petri dish should be stored upside down to stop drops of condensation falling onto the agar

Answer 7

- The antibodies would only attach to cancer cells - A radioactive source can then be used to target those cancer cells - So, there are fewer effects to non-cancerous cells

Answer 8

1) Inject animal with chosen antigen 2) Extract B-lymphocyte white blood cell and fuse with a myeloma (tumour) cell to form a hybridoma 3) Hybridoma can then divide rapidly and these clones produce lots of monoclonal antibodies

Answer 9

You can make them to bind to anything you want. So, you can target specific cells in the body (e.g. cancer cells)

Answer 10

Hybridoma Cell

Answer 11

Discovering the drug Developing the drug using..... Preclinical testing Clinical testing Approving drug by medical agency

Answer 12

1) Drugs are tested on human cells and tissues in the lab 2) Drug is tested on live animas to see if it works and how toxic it is and to find the best dosage

Answer 13

1) If the drug passes tests on animals, it's tested on human volunteers in a clinical trial 2) Firstly tested on healthy volunteers to make sure there are no harmful side effects 3) Drugs are then tested on the people suffering from the illness and the optimum dose is found (most effective with fewest side effects) 4) Patients put into 2 groups randomly. One is given placebo and the other is given new drug to allow for placebo effect 5) Trials are often double blind so neither the patient of doctor knows who is on drug or placebo so the doctors analysing the results aren't subconsciously influenced

Answer 14

Pros: Can completely treat heart problems Cons: Drugs taken to prevent donor heart being rejected can have side effects e.g. making you more vulnerable to infection Surgery is a major procedure with risk of bleeding, clots and infection

Answer 15

Pros: Can treat cardiovascular disease BY.. decreasing blood pressure and preventing blood clots Cons: HAs to be taken for whole life, serious side effects like liver damage, side effects like headaches and fainting

Answer 16

Pros: Can help reduce risks of heart attacks and strokes, no downsides/side effects Cons: Does not definitely prevent problems occurring

Answer 17

Cute Tigers Make Silly Excited Choices

Answer 18

* exposure to the {toxin/antigen/ pathogen/bacteria} (1) * stimulates an immune response (1) * production of memory lymphocytes (1)

Answer 19

- not everyone has been immunised (1) - immigration introduces people who are not immunised (1) - immunisation not fully effective (1) - immunity can decrease with age (1)

Answer 20

exponential growth

Answer 21

- Heart attack - Stroke - Heart disease - High blood pressure

Answer 22

* involved in defence against disease / part of immune system (1) * phagocytosis (1) * antibody / antitoxin production (1)

Answer 23

- On the part where you wee, there are monoclonal antibodies with blue beads attached, specific to the hormone HCG and are free to move around - The test strip also has monoclonal antibodies specific to HCG, by can't move around IF YOU ARE PREGNANT: - HCG hormone will bind to the antibodies on the blue beads - The urine moves up the stick carrying the hormone - The beads and HCG hormone bind to the antibodies on the test strip - So, the blue beads get stuck on the strip which turns it blue IF YOU ARE NOT PREGNANT: - Urine moves up the stick, carrying the blue beads - But, there's nothing to stick the blue beads to the test strip as the woman doesn't have the hormone HCG (so it doesn't turn blue)